FW: Library infrastructure

[Malcolm Wallace]

Johannes Waldmann <joe@informatik.uni-leipzig.de> writes:

> A friend told me recently that some interactive Prolog (?) systems 
> have a this nice feature: the user can ask for all identifiers
> (currently in scope) of a certain type (or mode? or was it LISP anyway?)
> (so  [a] -> [a]  should give you  reverse  and  tail).

See:
    Retrieving Reusable Software Components by Polymorphic Type,
    C. Runciman, I. Toyn, Journal of Functional Programming, 1(2),
    April 1991, pp191-211.

This was available in lazy FP systems before Haskell even appeared.
I wonder why no-one has ever implemented the idea for Haskell?
It seems like it would be useful.

Regards,
    Malcolm